The Australian feral pig is hardy, intelligent, cunning and endlessly adaptable -- fine qualities, perhaps, but not when they're possessed by an animal intent on breaking into your garden and wreaking utter havoc on your prized ornamentals. Keeping feral pigs out of your garden isn't just a matter of sticking a picket fence around your land and calling it a day. Pigs will use various ways and means to try and access your garden and the food and water within, so you should make sure that your anti-pig fence has the following qualities to maximise effectiveness:
Height and depth
Ungainly as they may appear, feral pigs are remarkably agile, and will jump if the situation calls for it. Feral hogs have been known to jump fences up to three feet in height, so make sure your fence stands taller than this.
However, your fence will also have to extend underground, as feral pigs are consummate diggers, easily capable of undermining a fence without the proper foundations. Make sure the bottom of your fence is firmly rooted in the ground to prevent pigs rooting around underneath it, and bury fence posts and corners to prevent them being easily uprooted and toppled
A charging feral pig carries a lot of weight and aggression behind it, so your fence should be made of materials capable of preventing a pig simply barging its way through. This rules out many standard wooden panel fences, but a sturdy, thick wooden fence with minimal gaps should keep out a determined pig. Wooden fences should be properly treated to prevent them being weakened by decay and the elements.
Metal fences aren't quite as nice to look at, but a simple wire mesh fence is an effective barrier to pigs. Using a metal fence will also make it easier to install electrified or barbed wire. Make sure that the mesh on your fence is tight enough to keep out curious snouts, and that the wires are strong and tightly-woven enough to prevent larger pigs bending wires to get through. Metal fences will also benefit from galvanised or polymer coatings to resist rust and oxidisation.
Electrification and barbed wire
Using anti-pig measures such as barbed wire and electrified wire on your fencing does not mean turning your garden into a concentration camp -- only small amounts of either wiring need to be installed to effectively deter pigs. A single barbed or electrified wire, mounted about two feet up the fence, is generally enough to keep out all but a starving pig -- at this height the first part of a pig to touch the wire will be its sensitive snout, providing enough of a shock to deter entry.